OKDOVICIAN TRILOBITES OF THE FAMILY 



TELEPHIDAE AND CONCERNED 



STRATIGRAPHIC CORRELATIONS 



By E. O. Ulrich ^ 



Associate in Paleontology, United States 'National Museum 



INTRODUCTION 



Previous work on Telephus. — The genus Telephus was established 

 by Barrande ^ for the Bohemian species T. fractus. Of this species 

 Barrande knew only the cranidium and the pygidium, and of the 

 former he mistook the long palpebral bands for the border of the 

 cheeks. Consequently he expressed himself as quite unable to place 

 the genus in his classification of the trilobites. Two years later 

 Angelin ^ described three species from Ordovician formations in 

 Norway and Sweden but added nothing toward fixing the systematic 

 position of Telephus. Some years later Billings * recognized the 

 genus on the west side of the Atlantic but, like his predecessors in 

 the field, failed to add anything of more than specific importance 

 to what had been known before. Many years later Reed ° described 

 a cranidium from the Girvan District in Scotland that he regarded 

 as specifically identifiable with the Bohemian T. fractus. In 1909 

 he described a new species, T. hihernicus, from an Ordovician forma- 

 tion in Ireland, and five years later ^ in the supplement to his mono- 



1 Tbig is one of many papers on trilobites for wbicb tbe author has worked out the 

 facts in the past 25 and more years but laclted the time to complete the manniscripta 

 and illustrations. Most of these unpublished works endeavored to present what was 

 known at the time of the species of a particular genus or family. At the earnest and 

 repeated solicitation of friends it is now planned to bring to date and publish as many 

 of these old manuscripts as possible without interfering too greatly with the paramount 

 duty of completing the long promised monographs on the Ozarkian and Canadian systems. 

 The present installment has become possible mainly through the gratefully accepted aid of 

 Dr. C. E. Resser, who made most of the photographs and assisted otherwise Id promoting 

 the effort. The originally brief discussion of the stratigraphy of the beds in which 

 species of Telephus occur has been greatly expanded and completely rewritten, so that 

 in the writer's opinion it has become the more important part of the paper. 



' Barrande, Joachim, 1852, Syst. Sil. du centre Boheme, vol. 1, p. 890. 



3 Angelin, N. P., 1854, Palaeontologia Scandinavica, p. 91. 



* Billings, E., 1805, Paleozoic fossils: Canada Geol. Survey, vol. 1, p. 291. 



5 Reed, F. R. Cowper, 1903, Paleontogr. Soc, p. 44. 



» Reed, F. R. Cowper, 1909, Geol. Soc. Londom Quart. Journ., vol. 65, p. 149 ; 1913. 

 Paleontogr. Soc, vol. 67, p. 16. 



No. 2818.— Proceedings U. S. National Museum, Vol. 76, Art. 21 



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